OFFSET
1,1
COMMENTS
Column 3 of A224038.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) - 3*a(n-2) - a(n-3) + 2*a(n-5).
Empirical g.f.: x*(1 - x)*(4 + x - 2*x^2 - 2*x^3) / (1 - 4*x + 3*x^2 + x^3 - 2*x^5). - Colin Barker, Aug 26 2018
EXAMPLE
Some solutions for n=3:
..0..0..1....0..0..0....0..0..0....0..0..0....0..0..0....0..1..1....0..0..0
..0..1..1....1..1..1....0..0..1....0..0..0....0..0..0....1..1..1....0..1..1
..1..1..1....0..1..1....1..1..1....0..0..1....0..1..1....1..1..1....0..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 30 2013
STATUS
approved